Views: 254 Author: BenQ Publish Time: 2024-04-23 Origin: https://www.benq.com/en-us/knowledge-center/knowledge/light-resistant-screens.html
Choosing the right projection screen is the first step to getting the most enjoyment from your home entertainment system. Even basic entry-level projectors require a flat surface to produce the best images. This article will explain different ambient light rejecting screens.
In this article we cover:
1.What is an Ambient Light Rejecting Screen?
2.Advantages of Light Rejecting Screens
3.What is a Fresnel Projector Screen?
4.How do I choose between a Fresnel projector screen and a black grid ALR screen?
Ambient Light Rejecting (ALR) projector screen is the common name for an ambient light suppression projector screen. Unlike normal projector screens that reflect less light by causing the light to bounce in all directions, ambient light suppression screens are designed to selectively reflect more of the projector's light back to the viewer, effectively re-integrating the ambient lighting, so that it doesn't interfere too much with the image quality, resulting in a brighter, clearer, more vivid picture. As a result, ALR projector screens are great for rooms where it is difficult to control the amount of ambient light, at the same time though ALR screens tend not to support projectors and ambient lights hitting the screen in the same direction.
*Please choose the proper ambient light rejecting screen according to the throw ratio of your projector.
Traditional projection screens rely on specular reflection, which causes problems with glare and the so-called spotlight effect. To counteract these issues, light rejecting screens feature enhanced anti-glare (AG) properties which diffuse reflection to eliminate spotlighting.
Screens without anti-glare properties exhibit spotlighting
Screens with anti-glare properties do not suffer from spotlighting
Regular projection screens also typically use flat screens or repeating optical structures, which contain major defects. Flat screens reflect much of the main projected light up towards the ceiling, causing diminished brightness and inadequate image quality, while screens with repeating optical structures result in areas of uneven brightness.
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Flat Screens - Projected light reflected toward the ceiling Repeating optical structures -Due to a centrally- focused design, the light from the top and bottom is uneven
Gradient Optical Structures - Because the angle of incoming light varies, only an adaptive design can effectively deliver light to the viewer, which requires gradient optical structures.
Fresnel Projector Screens are projector screens, specially designed for ultra-short throw TV projectors, that are able to divide ambient light from above and the sides of the screen. The optics behind Fresnel projector screens rely on spiral-like semicircle structures of various sizes on the surface of the screen that are able to redirect the path of the light from the projector, letting the image on the screen look brighter and more uniform within the range of its given viewing angle. These semicircular shapes only reflect rays coming from below them, which also happens to be the orientation from which most TV projectors project light onto their screens, making Fresnel Projector Screens ideal for said projectors. Another aspect of Fresnel projector screens that should be noted is that they need to be designed so that the semi-circular structures are directed as close as possible towards the projection lens, this is to ensure that the reflected light is concentrated towards the corresponding viewing area thereby enhancing the image’s brightness.
As discussed above Fresnel projector screens feature a surface full of semi-circular structures that only reflect light projected from a typical TV projector’s position, thereby bolstering image brightness and the effectiveness of its ambient light rejecting capabilities making the image quality similar to a traditional TV. Black grid ALR screens on the other hand features surfaces full of horizontally-placed miniscule prisms that similarly are meant to only reflect light from below as opposed to ambient light from above. Both types of screens are thus suitable for ultra-short throw TV projectors that are used in settings with ambient light to help enhance their image quality.
Screen Type | Black Grid Screen | Fresnel Screen |
Type of Ambient Light Rejected | Reject light from above | Reject light from three directions |
Percentage of Ambient Light Rejected | About 80% | About 90% |
Suitable Usage Setting | Bright ambient light from above, | Very bright ambient light all around |
View Angle | 160° or above | 120° or above |